U.S. patent number 10,238,585 [Application Number 14/353,497] was granted by the patent office on 2019-03-26 for oil-in-water emulsion sunscreen cosmetic.
This patent grant is currently assigned to SHISEIDO COMPANY, LTD.. The grantee listed for this patent is Taichi Harada, Yosuke Ikebe, Kahori Ishida. Invention is credited to Taichi Harada, Yosuke Ikebe, Kahori Ishida.
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United States Patent |
10,238,585 |
Ishida , et al. |
March 26, 2019 |
Oil-in-water emulsion sunscreen cosmetic
Abstract
The present invention is intended to provide an organic UV
absorber-free, non-chemical sunscreen cosmetic that contains
hydrophobized zinc oxide and/or hydrophobized titanium dioxide as a
UV scattering agent, specifically an oil-in-water emulsion
sunscreen cosmetic that provides excellent emulsion stability and
an excellent pleasant feel while maintaining high levels of UV
protection.
Inventors: |
Ishida; Kahori (Yokohama,
JP), Harada; Taichi (Yokohama, JP), Ikebe;
Yosuke (Yokohama, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Ishida; Kahori
Harada; Taichi
Ikebe; Yosuke |
Yokohama
Yokohama
Yokohama |
N/A
N/A
N/A |
JP
JP
JP |
|
|
Assignee: |
SHISEIDO COMPANY, LTD. (Tokyo,
JP)
|
Family
ID: |
48167610 |
Appl.
No.: |
14/353,497 |
Filed: |
October 10, 2012 |
PCT
Filed: |
October 10, 2012 |
PCT No.: |
PCT/JP2012/076185 |
371(c)(1),(2),(4) Date: |
April 23, 2014 |
PCT
Pub. No.: |
WO2013/061776 |
PCT
Pub. Date: |
May 02, 2013 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20140255323 A1 |
Sep 11, 2014 |
|
Foreign Application Priority Data
|
|
|
|
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Oct 27, 2011 [JP] |
|
|
2011-235612 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K
8/585 (20130101); A61K 8/60 (20130101); A61K
8/29 (20130101); A61K 8/731 (20130101); A61Q
17/04 (20130101); A61K 8/062 (20130101); A61K
8/361 (20130101); A61K 8/891 (20130101); A61K
8/27 (20130101); A61K 2800/30 (20130101); A61K
2800/623 (20130101) |
Current International
Class: |
A61K
8/60 (20060101); A61K 8/29 (20060101); A61K
8/27 (20060101); A61K 8/06 (20060101); A61Q
17/04 (20060101); A61K 8/891 (20060101); A61K
8/73 (20060101); A61K 8/58 (20060101); A61K
8/36 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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H09-255543 |
|
Sep 1997 |
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JP |
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2005-145972 |
|
Jun 2005 |
|
JP |
|
2005-247722 |
|
Sep 2005 |
|
JP |
|
2007-277191 |
|
Oct 2007 |
|
JP |
|
2010-222349 |
|
Oct 2010 |
|
JP |
|
2011-136965 |
|
Jul 2011 |
|
JP |
|
2010-070867 |
|
Jun 2010 |
|
WO |
|
WO-2010/149798 |
|
Dec 2010 |
|
WO |
|
Other References
The International Bureau of WIPO, "Notification of Transmittal of
Translation of the International Preliminary Report on
Patentability," issued in International Application No.
PCT/JP2012/076185, of which U.S. Appl. No. 14/353,497 is a U.S.
national phase entry, dated May 8, 2014. cited by
applicant.
|
Primary Examiner: Padmanabhan; Sreenivasan
Assistant Examiner: Sullivan; Danielle
Claims
The invention claimed is:
1. An organic UV absorber-free, oil-in-water emulsion sunscreen
cosmetic that comprises: (A) zinc oxide and/or titanium dioxide;
(B) isostearic acid; (C) a silicone containing a carboxyl group;
(D) a non-ionic surfactant; (E) sodium carboxymethyl cellulose; and
(F) water; wherein said (A) zinc oxide and/or titanium dioxide is:
hydrophobized with octyltriethoxysilane and/or
dimethylpolysiloxane; and homogeneously dispersed in an oil phase
with said (C) silicone containing a carboxyl group acting as a
dispersant; and wherein the dispersibility of the zinc oxide or the
titanium dioxide lowers without said (B) isostearic acid wherein
(C) the silicone containing a carboxyl group is carboxydecyl
trisiloxane.
2. The oil-in-water emulsion sunscreen cosmetic according to claim
1, wherein the contents of the components (A) to (E) with respect
to the total amount of the oil-in-water emulsion sunscreen cosmetic
are: 3 to 35 mass % for (A) the zinc oxide and/or the titanium
dioxide hydrophobized with octyltriethoxysilane and/or
dimethylpolysiloxane; 0.1 to 2 mass % for (B) the isostearic acid;
0.1 to 1.5 mass % for (C) the silicone containing a carboxyl group;
0.5 to 4.5 mass % for (D) the non-ionic surfactant; and 0.1 to 1
mass % for (E) the sodium carboxymethyl cellulose.
3. The oil-in-water emulsion sunscreen cosmetic according to claim
1, further comprising: (G) a natural polymer or a synthetic high
polymer.
4. The oil-in-water emulsion sunscreen cosmetic according to claim
2, further comprising: (G) a natural polymer or a synthetic high
polymer.
5. A method for making the organic UV absorber-free, oil-in-water
emulsion sunscreen cosmetic of claim 1, the method comprising the
steps of: hydrophobizing (A) the zinc oxide and/or titanium dioxide
with octyltriethoxysilane and/or dimethylpolysiloxane; and
dispersing the hydrophobized zinc oxide and/or titanium dioxide
homogeneously in an oil phase with (C) carboxydecyl trisiloxane
acting as a dispersant; wherein the dispersibility of the zinc
oxide or the titanium dioxide lowers without (B) the isostearic
acid.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a U.S. national stage application under
35 U.S.C. .sctn. 371 of International Patent Application No.
PCT/JP2012/076185 filed on Oct. 10, 2012, which claims the benefit
of foreign priority to Japanese Patent Application No. JP
2011-235612 filed on Oct. 27, 2011, the disclosures of all of which
are hereby incorporated by reference in their entireties. The
International Application was published in Japanese on May 2, 2013,
as International Publication No. WO 2013/061776 A1 under PCT
Article 21(2).
TECHNICAL FIELD
The present invention relates to oil-in-water emulsion sunscreen
cosmetics. Specifically, the invention relates to an organic UV
absorber-free, non-chemical sunscreen cosmetic that contains
hydrophobized zinc oxide and/or hydrophobized titanium dioxide as a
UV scattering agent, and in which the hydrophobized zinc oxide
and/or hydrophobized titanium dioxide are homogeneously and stably
dispersed in the oil phase to provide excellent emulsion stability
and an excellent pleasant feel.
BACKGROUND ART
Oil-in-water emulsion sunscreen cosmetics containing a
hydrophobized UV scattering agent dispersed in an internal phase
are useful as a formulation that can satisfy both a pleasant
moisturizing feel and a high SPF.
Zinc oxide and titanium dioxide are commonly used as UV scattering
agents (for example, Patent Citation 1). However, a technique that
homogeneously and stably disperses zinc oxide and titanium dioxide
in the oil component becomes very important in stably containing
these zinc oxide and titanium dioxide components in the internal
oil phase of an oil-in-water emulsion cosmetic.
On the other hand, sunscreen cosmetics (non-chemical sunscreens)
that contain no organic UV absorber generally have drawbacks in
terms of feeling. Specifically the products give a powdery or dry
feel because of the UV scattering agent dispersed in the external
oil phase of the water-in-oil emulsion composition. Patent Citation
2 discloses an organic UV absorber-free, non-chemical water-in-oil
sunscreen cosmetic that contains a volatile component, an organic
modified clay mineral, a spherical resin powder, a coating agent,
and a UV scattering agent (zinc oxide and/or titanium dioxide).
However, because the UV scattering agent is dispersed in the
external oil phase of the water-in-oil composition, this cosmetic
also has a very uncomfortable powdery or dry feel.
CITATION LIST
Patent Literature
Patent Citation 1: JP 2010-222349 A
Patent Citation 2: JP H9-255543 A
SUMMARY OF INVENTION
Technical Problem
Under these circumstances, the present inventors conducted
intensive studies to provide an organic UV absorber-free,
non-chemical sunscreen cosmetic that contains hydrophobized zinc
oxide and/or hydrophobized titanium dioxide as a UV scattering
agent, and in which excellent emulsion stability and an excellent
pleasant feel can be realized by the high dispersibility of the
hydrophobized zinc oxide and/or hydrophobized titanium dioxide. It
was found after these studies that a sunscreen cosmetic with an
oil-in-water emulsion composition containing a combination of
specific components can provide an organic UV absorber-free,
non-chemical oil-in-water emulsion sunscreen cosmetic in which
large amounts of hydrophobized zinc oxide and/or hydrophobized
titanium dioxide can be stably dispersed in the internal oil phase,
and which has excellent emulsion stability (UV scattering agent
dispersion stability) and an excellent pleasant feel while
maintaining high levels of UV protection. The present invention was
completed on the basis of this finding.
It is an object of the present invention to provide an organic UV
absorber-free, non-chemical sunscreen cosmetic that contains
hydrophobized zinc oxide and/or hydrophobized titanium dioxide as a
UV scattering agent, specifically an oil-in-water emulsion
sunscreen cosmetic that provides excellent emulsion stability and
an excellent pleasant feel while maintaining high levels of UV
protection.
Solution to Problem
Specifically, the present invention provides an organic UV
absorber-free, oil-in-water emulsion sunscreen cosmetic that
includes:
(A) zinc oxide and/or titanium dioxide hydrophobized with
octyltriethoxysilane and/or dimethylpolysiloxane;
(B) a liquid higher fatty acid;
(C) a silicone of a structure containing a carboxyl group, or a
sugar ester;
(D) a non-ionic surfactant;
(E) sodium carboxymethyl cellulose; and
(F) water.
In the oil-in-water emulsion sunscreen cosmetic provided by the
present invention, the contents of the components (A) to (E) with
respect to the total amount of the oil-in-water emulsion sunscreen
cosmetic are:
3 to 35 mass % for (A) the zinc oxide and/or the titanium dioxide
hydrophobized with octyltriethoxysilane and/or
dimethylpolysiloxane;
0.1 to 2 mass % for (B) the liquid higher fatty acid;
0.1 to 1.5 mass % for (C) the silicone of a structure containing a
carboxyl group, or the sugar ester;
0.5 to 4.5 mass % for (D) the non-ionic surfactant; and
0.1 to 1 mass % for (E) the sodium carboxymethyl cellulose.
Advantageous Effects of Invention
The present invention can provide an organic UV absorber-free,
non-chemical sunscreen cosmetic that contains hydrophobized zinc
oxide and/or hydrophobized titanium dioxide as a UV scattering
agent, specifically an oil-in-water emulsion sunscreen cosmetic
that provides excellent emulsion stability and an excellent
pleasant feel while maintaining high levels of UV protection.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 represents UV spectra of Example 3 and Comparative Example
3.
DESCRIPTION OF EMBODIMENTS
The present invention is described below.
(A) Zinc Oxide and/or Titanium Dioxide Hydrophobized with
Octyltriethoxysilane and/or Dimethylpolysiloxane
In the present invention, the hydrophobizing agents of zinc oxide
and/or titanium dioxide are limited to octyltriethoxysilane and/or
dimethylpolysiloxane. Using other hydrophobizing agents is
detrimental to the dispersibility of the zinc oxide and/or titanium
dioxide. The dimethylpolysiloxane has a degree of polymerization of
preferably 100 to 1000.
The method used to hydrophobize zinc oxide and/or titanium dioxide
is not particularly limited, and a surface treatment is performed
according to an ordinary method. For example, zinc oxide and/or
titanium dioxide may be mixed and stirred in octyltriethoxysilane
and/or dimethylpolysiloxane for a certain time period, and filtered
to produce zinc oxide and/or titanium dioxide hydrophobized with
octyltriethoxysilane and/or dimethylpolysiloxane. Note that
dimethylpolysiloxane is used in a liquid form that allows for
hydrophobization.
The zinc oxide and/or titanium dioxide used in the present
invention are fine powders, preferably fine powders having an
average particle diameter of 10 to 80 nm.
The total content of the zinc oxide and/or titanium dioxide
hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane
is preferably 3 to 35 mass %, further preferably 5 to 30 mass %,
most preferably 12 to 25 mass % with respect to the total amount of
the oil-in-water emulsion sunscreen cosmetic.
The dispersibility of the zinc oxide and/or titanium dioxide may be
adversely affected when the content of the zinc oxide and/or
titanium dioxide hydrophobized with octyltriethoxysilane and/or
dimethylpolysiloxane falls outside of these ranges.
(B) Liquid Higher Fatty Acid
The liquid higher fatty acid used in the present invention may be,
for example, isostearic acid, oleic acid, linoleic acid, or
linolenic acid. Particularly preferred is isostearic acid.
The liquid higher fatty acid as the oil component of the present
invention is a component that, together with the dispersant
component (C), forms an internal oil phase in the oil-in-water
emulsion sunscreen cosmetic.
In the present invention, the hydrophobized zinc oxide or titanium
dioxide (component (A)) is homogeneously dispersed in an oil phase
formed by the oil component. The dispersibility of the zinc oxide
or titanium dioxide lowers without the liquid higher fatty
acid.
In the present invention, the hydrophobized zinc oxide or
hydrophobized titanium dioxide (component (A)) is fully dispersed
in the oil phase component to form an oil phase.
The oil component forming an oil phase may contain other oil
components such as hydrocarbon oil (e.g., vaseline, and squalane),
provided that such addition is not detrimental to the advantageous
effects of the present invention. It is also preferable to contain
a volatile oil component. Examples of a volatile oil component
include a hydrocarbon oil of a relatively low molecular weight, a
linear silicone of a relatively low molecular weight, and a cyclic
silicone of a relatively low molecular weight. Particularly
preferred are light liquid isoparaffin, isododecane, isohexadecane,
and volatile dimethylpolysiloxane, or cyclic polysiloxane (for
example, octamethylcyclotetrasiloxane,
decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and
hexadecamethylcycloheptasiloxane).
The content of the liquid higher fatty acid is preferably 0.1 to 2
mass %, further preferably 0.3 to 1.8 mass %, most preferably 0.5
to 1.5 mass % with respect to the total amount of the oil-in-water
emulsion sunscreen cosmetic.
The dispersibility of the zinc oxide and/or titanium dioxide may be
adversely affected when the liquid higher fatty acid content falls
outside of these ranges.
(C) Silicone of Structure Containing Carboxyl Group or Sugar Ester
(Dispersant)
The silicone of a structure containing a carboxyl group used in the
present invention may be, for example, carboxydecyl trisiloxane, or
alkylacrylate copolymer methylpolysiloxane ester. Particularly
preferred is carboxydecyl trisiloxane.
The sugar ester used in the present invention may be, for example,
sorbitan sesquiisostearate, dipentaerythritol fatty acid ester,
polyoxyethylene sorbitan monooleate, or polyoxyethylene sorbitan
monostearate. Particularly preferred is sorbitan
sesquiisostearate.
In the present invention, the component (C) serves as a dispersant
for homogeneously and stably dispersing the hydrophobized zinc
oxide and/or hydrophobized titanium dioxide in the oil phase.
The content of the silicone of a structure containing a carboxyl
group or the sugar ester is preferably 0.1 to 1.5 mass %, further
preferably 0.2 to 1.2 mass %, most preferably 0.3 to 1.0 mass %
with respect to the total amount of the oil-in-water emulsion
sunscreen cosmetic.
The dispersibility of the zinc oxide and/or titanium dioxide may be
adversely affected when the content of the silicone of a structure
containing a carboxyl group or the sugar ester falls outside of
these ranges.
(D) Non-Ionic Surfactant
The non-ionic surfactant used in the present invention is a
component contained as an emulsifier for production of a stable
oil-in-water emulsion composition. Preferably, a hydrophilic
non-ionic surfactant is used in the present invention.
Specific examples of hydrophilic non-ionic surfactants include
POE-sorbitan fatty acid esters (for example, POE-sorbitan
monooleate, POE-sorbitan monostearate, POE-sorbitan tetraoleate);
POE-sorbitol fatty acid esters (for example, POE-sorbitol
monolaurate, POE-sorbitol monooleate, POE-sorbitol pentaoleate,
POE-sorbitol monostearate); POE-glycerin fatty acid esters (for
example, POE-monooleates such as POE-glycerin monostearate,
POE-glycerin monoisostearate, and POE-glycerin triisostearate);
POE-fatty acid esters (for example, POE-distearate,
POE-monodioleate, ethylene glycol distearate); POE-alkyl ethers
(for example, POE-lauryl ether, POE-oleyl ether, POE-stearyl ether,
POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholestanol
ether); Pluronic types (for example, Pluronic); POE.PPP-alkyl
ethers (for example, POE.POP-cetyl ether, POE.POP-2-decyltetradecyl
ether, POE.POP-monobutyl ether, POE.POP-hydrogenated lanolin,
POE.POP-glycerin ether); tetra POE.tetra POP-ethylenediamine
condensation products (for example, Tetronic); POE-castor
oil-POE-hydrogenated castor oil derivatives (for example,
POE-castor oil, POE-hydrogenated castor oil, POE-hydrogenated
castor oil monoisostearate, POE-hydrogenated castor oil
triisostearate, POE-hydrogenated castor oil monopyroglutamic acid
monoisostearic acid diester, POE-hydrogenated castor oil maleic
acid); POE-beeswax-lanolin derivatives (for example, POE-sorbitol
beeswax); alkanolamides (for example, coconut oil fatty acid
diethanolamide, lauric acid monoethanolamide, fatty acid
isopropanolamide); POE-propylene glycol fatty acid esters;
POE-alkylamines; POE-fatty acid amides; sucrose fatty acid esters;
alkylethoxydimethylamineoxide; and trioleyl phosphoric acid.
Examples of lipophilic non-ionic surfactants include sorbitan fatty
acid esters (for example, sorbitan monooleate, sorbitan
monoisostearate, sorbitan monolaurate, sorbitan monopalmitate,
sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate,
diglyceryl sorbitan penta-2-ethylhexanoate, diglyceryl sorbitan
tetra-2-ethylhexanoate); glycerin polyglycerin fatty acids (for
example, cotton seed oil fatty acid monoglyceride, glyceryl
monoerucate, glyceryl sesquioleate, glyceryl monostearate,
.alpha.,.alpha.'-glyceryl oleate pyroglutamate, glyceryl
monostearate malate); propylene glycol fatty acid esters (for
example, propylene glycol monostearate); hydrogenated castor oil
derivatives; and alkyl glyceryl ethers.
The content of the non-ionic surfactant is preferably 0.5 to 4.5
mass %, further preferably 1.0 to 4.0 mass % with respect to the
total amount of the oil-in-water emulsion sunscreen cosmetic.
The stability of the oil-in-water emulsion cosmetic may lower when
the non-ionic surfactant content falls outside of these ranges.
(E) Sodium Carboxymethyl Cellulose
The sodium carboxymethyl cellulose used in the present invention is
an essential component for stably containing large amounts of the
UV scattering agent (hydrophobized zinc oxide and/or hydrophobized
titanium dioxide) in the internal phase of the oil-in-water
emulsion composition of the present invention, and maintaining
excellent emulsion stability. It has been extremely difficult with
conventional techniques to stably contain large amounts of UV
scattering agent (hydrophobized zinc oxide and/or hydrophobized
titanium dioxide) in the internal phase of an oil-in-water emulsion
composition.
With the combination of the essential components (A) to (E) of the
present invention, the sodium carboxymethyl cellulose contained as
component (E) allows large amounts of the UV scattering agent
(hydrophobized zinc oxide and/or hydrophobized titanium dioxide) to
be stably contained, and high levels of UV protection (high SPF)
can be achieved while maintaining excellent emulsion stability,
without containing an organic UV absorber. This is the key
advantage of the present invention.
The content of the sodium carboxymethyl cellulose is preferably 0.1
to 1 mass %, further preferably 0.2 to 0.8 mass %, most preferably
0.3 to 0.6 mass % with respect to the total amount of the
oil-in-water emulsion sunscreen cosmetic.
It may not be possible to stably contain large amounts of the UV
scattering agent (hydrophobized zinc oxide and/or hydrophobized
titanium dioxide) when the sodium carboxymethyl cellulose content
falls outside of these ranges. In this case, the product may fail
to provide high levels of UV protection, and may not be useful as a
non-chemical sunscreen cosmetic.
(F) Water
The water used in the present invention is not particularly
limited. Specific examples include purified water, and ion-exchange
water.
Water is a component that, together with other aqueous components,
forms an external aqueous phase in the oil-in-water emulsion
sunscreen cosmetic.
The water content is appropriately decided according to the content
of the oil component forming the internal oil phase, and is
preferably 20 to 55 mass %, further preferably 25 to 45 mass % with
respect to the total amount of the oil-in-water emulsion sunscreen
cosmetic.
The stability of the oil-in-water emulsion cosmetic may suffer, or
a pleasant moisturizing feel may not be obtained, when the water
content falls outside of the foregoing ranges.
Containing No Organic UV Absorber
The oil-in-water emulsion sunscreen cosmetic of the present
invention is a non-chemical sunscreen cosmetic that does not
contain any organic UV absorber. Despite that an organic UV
absorber is not contained, the oil-in-water emulsion sunscreen
cosmetic of the present invention can provide high levels of UV
protection (high SPF) because of the large amounts of the UV
scattering agent stably contained therein.
The following lists include examples of specific compounds
typically contained as organic UV absorbers in common sunscreen
cosmetics. However, none of these organic UV absorbers are
contained in the present invention.
(1) Benzoic Acid UV Absorber
Examples include para-aminobenzoic acid (hereinafter, simply
"PABA"), PABA monoglycerin ester, N,N-dipropoxy PABA ethyl ester,
N,N-diethoxy PABA ethyl ester, N,N-dimethyl PABA ethyl ester,
N,N-dimethyl PABA butyl ester, and N,N-dimethyl PABA ethyl
ester.
(2) Anthranilate UV Absorber
Examples include homomenthyl-N-acetylanthranilate.
(3) Salicylate UV Absorber
Examples include amyl salicylate, menthyl salicylate, homomenthyl
salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate,
and p-isopropanol phenyl salicylate.
(4) Cinnamate UV Absorber
Examples include octyl cinnamate, ethyl-4-isopropyl cinnamate,
methyl-2,5-diisopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate,
methyl-2,4-di isopropyl cinnamate, propyl-p-methoxy cinnamate,
isopropyl-p-methoxy cinnamate, isoamyl-p-methoxy cinnamate,
octyl-p-methoxy cinnamate (2-ethylhexyl-p-methoxy cinnamate),
2-ethoxyethyl-p-methoxy cinnamate, cyclohexyl-p-methoxy cinnamate,
ethyl-.alpha.-cyano-.beta.-phenyl cinnamate,
2-ethylhexyl-.alpha.-cyano-.beta.-phenyl cinnamate, and glyceryl
mono-2-ethylhexanoyl-di-p-methoxy cinnamate.
(5) Triazine UV Absorber
Examples include bis-resorcinyl triazine.
Further specific examples include
bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-tria-
zine, and
2,4,6-tris{4-(2-ethylhexyloxycarbonyl)anilino}-1,3,5-triazine.
(6) Other Organic UV Absorber
Examples include 3-(4'-methylbenzylidene)-d, 1-camphor,
3-benzylidene-d, 1-camphor, 2-phenyl-5-methylbenzoxazole,
2,2'-hydroxy-5-methylphenylbenzotriazole,
2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole,
2-(2'-hydroxy-5'-methylphenyl)benzotriazole, dianisoylmethane,
4-methoxy-4'-t-butyldibenzoylmethane,
5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one, and pyridazine
derivatives such as dimorpholino pyridazinone.
Oil-in-Water Emulsion Cosmetic
In addition to the foregoing essential components, the oil-in-water
emulsion sunscreen cosmetic of the present invention may
appropriately contain components contained in common cosmetics,
provided that it is not detrimental to the advantageous effects of
the present invention. Examples of such additional components
include moisturizers, thickeners, powders, alcohols, natural
polymers, synthetic high polymers, sugars, antioxidants, buffers,
various extracts, stabilizers, preservatives, dyes, and
flavors.
In the oil-in-water emulsion sunscreen cosmetic producing process
of the present invention, the zinc oxide and/or titanium dioxide
hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane
(component (A)) are dispersed to form an oil phase by being mixed
and stirred in an oil component containing the highly dispersive
liquid higher fatty acid (component (B)) and the dispersant
(component (C)), using an HM mixer or the like. On the other hand,
water (component (F)), the hydrophilic non-ionic surfactant
(component (D)), the sodium carboxymethyl cellulose (component
(E)), and aqueous components such as ethanol, a thickener, and a
moisturizer are mixed to form an aqueous phase. The aqueous phase
and the oil phase are then emulsified by using an ordinary method
to provide the oil-in-water emulsion sunscreen cosmetic of the
present invention.
The oil-in-water emulsion sunscreen cosmetic of the present
invention is an emulsion composition with exceptional emulsion
stability.
The non-chemical oil-in-water emulsion sunscreen cosmetic of the
present invention uses zinc oxide and/or titanium dioxide powder as
a UV scattering agent, and these are homogeneously dispersed in the
oil phase. The non-chemical oil-in-water emulsion sunscreen
cosmetic of the present invention thus does not give a powdery
feel, but has a very pleasant moisturizing feel, making it
preferable for use as, for example, a sunscreen emulsion, or a
sunscreen cream.
Further, because the zinc oxide or titanium dioxide may be stably
contained in large amounts, the non-chemical oil-in-water emulsion
sunscreen cosmetic of the present invention does not give a powdery
feel, and can provide high levels of UV protection even if a
pleasant moisturizing feel is given priority. The non-chemical
oil-in-water emulsion sunscreen cosmetic of the present invention
can thus be expected to provide levels of UV protection comparable
to or greater than that of an oil-in-water emulsion sunscreen
cosmetic that does not prioritize a pleasant feel.
EXAMPLES
The present invention is described below in greater detail using
Examples. It should be noted, however, that the present invention
is not limited by the descriptions of the following Examples. In
the following, contents are in mass % with respect to the total
amount, unless otherwise stated.
Emulsions (oil-in-water emulsion sunscreen cosmetics) were produced
with the formulations presented in Tables 1 and 2, using an
ordinary method. These were evaluated in the manner described
below.
Emulsion Stability: Dispersibility of Hydrophobized Zinc Oxide
and/or Hydrophobized Titanium Dioxide
The emulsions of Examples and Comparative Examples immediately
after production were each charged into a cylindrical container in
about half the volume of the container, and rotated at 45 rpm for 2
hours at room temperature (25 to 30.degree. C.). The dispersed
state of the hydrophobized zinc oxide and/or hydrophobized titanium
dioxide was then visually observed with a light microscope (400
times magnification), and examined according to the following
evaluation criteria.
Evaluation Criteria
Good: There was no state change after the test, and the emulsion
state was stable. Specifically, the fine particles of hydrophobized
zinc oxide or titanium dioxide were homogeneously dispersed in the
oil phase.
Acceptable: The fine particles of hydrophobized zinc oxide or
titanium dioxide were not homogeneously dispersed in the oil phase,
and were unevenly distributed.
Poor: The hydrophobized zinc oxide and/or hydrophobized titanium
dioxide escaped from the dispersed oil phase to the aqueous
phase.
Powdery Feel
A demonstration test was conducted by applying the emulsions to the
arm of 10 trained panelists. The results were evaluated according
to the following criteria.
Evaluation Criteria
Good: At least 8 out of the 10 testers felt no powdery feel.
Acceptable: 5 to 7 out of the 10 testers felt no powdery feel.
Poor: Less than 5 out of the 10 testers felt no powdery feel.
Moisturizing Feel
A demonstration test was conducted by applying the emulsions to the
arm of 10 trained panelists. The results were evaluated according
to the following criteria.
Evaluation Criteria
Good: At least 8 out of the 10 testers felt a moisturizing
feel.
Acceptable: 5 to 7 out of the 10 testers felt a moisturizing
feel.
Poor: Less than 5 out of the 10 testers felt a moisturizing
feel.
TABLE-US-00001 TABLE 1 Com. Ex. 1 Com. Ex. 2 Ex. 1 Ex. 2 Ex. 3 Ex.
4 Water F (1) Water Remainder Remainder Remainder Remainder
Remainder Remainder Alcohol (2) Ethanol 5 5 5 5 5 5 Moisturizer (3)
Glycerin 3 3 3 3 3 3 Thickener (4) Succinoglycan 0.3 0.3 0.3 0.3
0.3 0.3 (5) (Dimethylacrylamide/ 0.3 0.3 0.3 0.3 0.3 0.3 sodium
acryloyl dimethyl taurate)crosspolymer Stabilizer E (6) Sodium 0
0.1 0.2 0.3 0.5 0.3 carboxymethyl cellulose Surfactant D (7)
Polyoxyethylene 3 3 3 3 3 3 hydrogenated castor oil Oil component
(8) Squalane 10 10 10 10 10 10 (9) Glyceryl 10 10 10 10 10 10
tri(caprylate/caprate) (10) Dimethylpolysiloxane 5 5 5 5 5 5 (6 cs)
Dispersant C (11) Sorbitan 0.5 0.5 0.5 0.5 0.5 sesquiisostearate C
(12) Carboxydecyl 0.5 trisiloxane Liquid higher B (13) Isostearic
acid 1 1 1 1 1 1 fatty acid Hydrophobized A (14)
Octyltriethoxysilane- 16 16 16 16 16 16 zinc oxide treated zinc
oxide Hydrophobized A (15) Octyltriethoxysilane- 4 4 4 4 4 4
titanium dioxide treated titanium dioxide Powder (16) Silica 1 1 1
1 1 1 Buffer (17) Sodium citrate Appropriate Appropriate
Appropriate Appropriate Appropriate Appro- priate amount amount
amount amount amount amount (18) Citric acid Appropriate
Appropriate Appropriate Appropriate Appropriate Appropri- ate
amount amount amount amount amount amount Chelating agent (19)
Chelating agent Appropriate Appropriate Appropriate Appropriate
Appropriate Appropr- iate amount amount amount amount amount amount
Preservative (20) Phenoxy ethanol 0.5 0.5 0.5 0.5 0.5 0.5 Emulsion
stability Poor Acceptable Good Good Good Good
Method of Production Preparation of Aqueous Phase
Components (17), (18), (19), and (20) were added and dissolved in
component (1). Components (4), (5), and (6) were wetted with
component (3), and the resultant was mixed with component (1).
Preparation of Oil Phase
Components (8), (9), (10), (11), (12), and (13) were homogeneously
mixed, components (14) and (15) were added to the mixture, and the
resultant was dispersed with an HM mixer.
Preparation of Oil-in-Water Emulsion Composition
Component (7) was mixed with the aqueous phase (70.degree. C.), and
the oil phase was emulsified. After adding the parts of components
(2) and (16) as a mixture, the whole was cooled to obtain an
emulsion.
TABLE-US-00002 TABLE 2 Com. Ex. 3 Ex. 3 Water-in-oil Oil-in-water
emulsion emulsion Water F (1) Water Remainder Remainder Alcohol (2)
Ethanol 5 5 Moisturizer (3) Glycerin 3 3 Thickener (4)
Succinoglycan 0 0.3 (5) (Dimethylacrylamide/ 0 0.3 sodium acryloyl
dimethyl taurate) crosspolymer (6) Dimethyl distearyl 2 0 ammonium
hectorite Stabilizer E (7) Sodium carboxy- 0 0.3 methyl cellulose
Surfactant D (8) Polyoxyethylene 0 3 hydrogenated castor oil (9)
Lauryl PEG-9 3 0 polydimethylsiloxy ethyldimethicone Oil (10)
Squalane 2 10 component (11) Glyceryl 2 10 tri(caprylate/caprate)
(12) 10 0 Decamethylcyclopenta- siloxane (13) Dimethylpoly- 5 5
siloxane (6 cs) Dispersant C (14) Sorbitan sesquiiso- 0.5 0.5
stearate Liquid B (15) Isostearic acid 1 1 higher fatty acid Hydro-
A (16) Octyltriethoxy- 16 16 phobized silane-treated zinc zinc
oxide oxide Hydro- A (17) Octyltriethoxy- 4 4 phobized
silane-treated titanium titanium dioxide dioxide Powder (18) Silica
1 1 Buffer (19) Sodium citrate Appropriate Appropriate amount
amount (20) Citric acid Appropriate Appropriate amount amount
Chelating (21) Chelating agent Appropriate Appropriate agent amount
amount Preservative (22) Phenoxy ethanol 0.5 0.5 Feeling Powdery
feel Poor Good (n = 10) Moisturizing feel Poor Good UV The levels
of UV protec- Solid circle Solid spectrum tion were essentially the
diamond same, as shown in the UV spectra of FIG. 1.
Method of Production
Emulsions (oil-in-water emulsion sunscreen cosmetics) of Example 3
and Comparative Example 3 were produced according to the producing
method of Examples presented in Table 1.
It can be seen from Tables 1 and 2 that the oil-in-water emulsion
sunscreen cosmetics of Examples 1 to 4 containing all of the
essential components of the present invention excelled in both
hydrophobic emulsion stability and pleasant feel.
The oil-in-water emulsion sunscreen cosmetics of Example 3 and
Comparative Example 3 that contained the same amounts of the
hydrophobized zinc oxide and hydrophobized titanium dioxide as a UV
scattering agent had essentially the same levels of organic UV
absorber protection as observed in the UV spectra. As demonstrated
above, the levels of UV protection remain the same, and do not drop
even when a pleasant feel is given priority as in Example 3.
The configuration of the present invention allows large amounts of
hydrophobized zinc oxide and hydrophobized titanium dioxide to be
stably contained as a UV scattering agent in the oil-in-water
emulsion composition, and provides a pleasant feel. High levels of
UV protection can thus be obtained as desired by increasing the UV
scattering agent content.
The emulsions of Examples 1 to 4 of the present invention represent
oil-in-water emulsion sunscreen cosmetics that do not give a
powdery feel, but provide a pleasant moisturizing feel. These
oil-in-water emulsion sunscreen cosmetics were also able to
suppress the attribute that the whiteness of the UV scattering
agent becomes noticeable upon application.
INDUSTRIAL APPLICABILITY
The present invention can provide an organic UV absorber-free,
non-chemical sunscreen cosmetic that contains hydrophobized zinc
oxide and/or hydrophobized titanium dioxide as a UV scattering
agent, specifically an oil-in-water emulsion sunscreen cosmetic
that provides excellent emulsion stability and an excellent
pleasant feel with the hydrophobized zinc oxide and/or
hydrophobized titanium dioxide homogeneously and stably dispersed
as a UV scattering agent in the oil phase.
According to the present invention, a non-chemical sunscreen
cosmetic that provides high levels of UV protection can be designed
without containing an organic UV absorber, because the cosmetic can
stably contain large amounts of hydrophobized zinc oxide and/or
hydrophobized titanium dioxide as a UV scattering agent. Further,
because the cosmetic does not give a powdery feel, but provides a
pleasant moisturizing feel, the present invention is very useful as
an oil-in-water emulsion sunscreen cosmetic.
* * * * *